Stylus mounting for reproducers



Dec. 11 1923.

C. SCRABIC STYLUS MOUNTING FOR REPRODUCERS Filed April 5, 1922 PatentedDee. M, 19230 anaestra'ranr u CARI; SCRABIC, F URBANA, 01 E110.

STYLUS MOUNTING FOR REPRODUGERS.

Application filed April 3, 1922. Serial .No. 548,977.

To all whom it may concern:

Be it known that CARL SoRABio, a citizen of the United States, residingat Urbana, in the county of Champaign and State of Ohio,

a has invented certain new and useful Improvements in Stylus Mountin sfor Reproducers, of which the following 1s a specification.

This invention relates to an improved 1o stylus mounting for thereproducer or a sound box of a. talking machine, or other soundproducing instrument, and has for its primary object the provision of amounting of an extremely sensitive character, and

us yet of practical and durable formation, which will enable a stylusbar associated therewith to respond to all including the minutesecondary, sound undulations provided in physical form within thegrooves 2a of talking machine records.

Another object of the invention resides in the provision; of an improvedstylus mounting which will not only be capable of oscillating about asubstantially horizontal 2a pivotal axis but will also be capable ofmovmg for a limited distance in any direction for the purpose ofenabling the stylus to properly and accurately respond to themulti-forin sound undulations of a record.

In a reproducer or sound box of usual form the stylusv bar is ordinarilymounted upon the frame or casing of a reproducer so that the stylus barwill be permitted to vibrate or oscillate on a single plane. As

85 a result of extended experiments it ismy belief that this ordinaryconstruction does not result in the reproduction of all of the soundwaves physically imposed or provided upon a record, since these waves ina lateral cut record not only provide horizontally extending projectionsor undulations of a major character o but include secondary sound waveimpressions which extend on various angles or planes to the major im- 4pressions, and which are not recorded or reproduced by astylus bar fixedto oscillate in a single plane. The present invention, therefore,consists in rovlding a stylus bar mounting which inc udes a air ofoutwardl extending studs carried thereby and capab e of being receivedwithin bearin sockets provided therefor in the casing o the reproducer,the said studs constituting fixed trunnions which enable the stylus barto oscillate upon a. main plane, the ends of the studs being receivedwithin sleeves formed from rubber or other compressible material whichwill admit of slight movement on the part of the stylus bar in anydirection, so that the needle of the stylus bar will respond to soundundulations of any character provided upon a record and will movefaithfully in close conformity with the manifold and varying physicalchar; acteristics of such undulations so as to bring forth andaccurately reproduce the fundamental and over tones thereof.

Another object of the invention resides in forming the trunnion studs ofthe main stylus bar axis with transversely extending pins which arereceived within the compressible sleeves of the mounting, the said pinsserving, by cooperation with the resilient sleeves to maintain thestylus bar in a true normal position and to provide a graduallyincreasing resistance to the stylus bar as the latter oscillates fromits normal or neutral position. I 4

Other objects of the invention rest in the provision of an improved andsimplified construction for admitting of the above set forth functionsand others, and wherein the assembly of the stylus and mounting inconnection with a reproducer can be easily and properly carried out, theconstruction of the mounting being extremely simple so that unskilledlabor may be employed in completing the operation and to permit thelatter to be performed accurately mbut a minimum of time.

With these and other objects in view, as will appear as the descriptionproceeds, the invention accordingly consists in the novel features ofconstruction, combinations of elements, and arrangements of parts,hereinafter to be fully described and articularly pointed out in theappended claims.

In the accompanying drawings, forming a part. of this specification, andin which similar characters of reference denote like and correspondingparts throughout the several views thereo Figure 1 is a side elevationof a talking machine reproducer provided with the improved stylus barmounting comprising 6* the present invention, I

tilt

Fi re 2 is a transverse horizontal sectiona view taken on the line 2-2of Figure 1 Figure 3 is a vertical transverse sectional view on the line3-3 of Figure 1,

Figure 4 is a perspective view of the stylus bar,

Figure 5 is a similar view of one of the sleeves employed in the pivotalmounting of the stylus bar,

Figure 6 is a similar view of one of the retaining blocks employed inthe mounting,

Figure 7 is a diagrammatic view on a greatly enlarged scale of the soundundulations of a record groove.

.Referring more particularly to the specific embodiment of the inventionillustrated in the accompanying drawings,the numeral 1 designates areproducer or sound ,box of the type employed in conjunction withtalking machines, and wherein is provided the usualmetallio casing orframe 2 having suitably mounted therein for vibration a diaphra- 3. Thecasing through the medium 0 a peculiarly formed mounting, hereinafterspecifically described, pivotally carries a stylus bar 4, which has itsupper end formed to be secured to or engage with the axial portion ofthe diaphragm 3, while the lower end of the stylus bar is suitablyenlarged and provided with a socket for the reception of a removableneedle 5 of any ordinary construction, the needle being retained withinthe stylus bar socket b means of the usual thumb screw 6. By isconstruction the stylus will be permitted to oscillate as usual inconformity with the sound undulations of a record groove and will,therefore, set up vibration on the part of the diaphragm 3, wherebyatmospheric disturbances within the sound box will be created andamplified by usual appliances.

As shown diagrammatically in Figure 7 a record groove of the so calledlateral cut variety is provided with sound undulations 7 suitably formedin said groove by any ordinary recording process which need not beherein described These undulations possess major and minor variations,the major variations are designated bythe numeral 8 and are of maximumdepth and extend generally, 1n lateral out records, on a horizontal vplane. I These variations, according to my experiments, are the onesthat are reproduced by an ordinary stylus bar, which is fixed to pivotina single plane, but which do not respond to the minor variations 9, inwhich are, included the fine over-tones and other delicate tonalshadings which should be reproduced to insure-a fair degree ofnaturalness. It will be observed that the minor variations may be insetor disposed on var ing planes with respect to the major variations, andtherefore I provide a mounting for the stylus bar which will enable itsneedle extremity to follow closely the undulating or serrated outlinesof both the major and minor variations.

To secure these results the casing of the reproducer is provided with adepending web 10, in which is formed a pair of space sockets 11,separated b an enlarged recess 12 provided centrally in the web 10. Thesockets 11 open into the recess 12 and are also provided with openbottom portions, the web 10 being extended so as to form the socketswith top, side and end walls 13, 14 and 15 respectively. The stylus bar4 has its lower enlarged extremity 16, above the needle 5, provided witha fixed transversely extending stud 17, which has its ends projectedlaterally from said stylus bar to constitute trunnions by means of whichthe stylus bar may be supported for vibration in connection withthereproducer. The outer ends of the studs 17 are received within thespaced sockets 11 of the web 10, and the said outer ends of the studs,which are received within the sockets 11, are provided with fixedtransversely extending pins 18, extending on planes at right angles tothe longitudinal axis of the studs 17. These pins are formed to receivecompressible sleeves 19, which are ordinarily formed from rubber and arepositioned within curved depressions 20 provided in the walls ofretaining blocks 21.

By this construction it will be observed that when the blocks 21 aresecured within the sockets 11, which is accomplished by means of thescrews 22 the stylus bar will be so mounted that the same will oscillatefrom a position defined by the studs 17 and may freely vibrate back andforth in response to the undulations of the major variations 8, in amanner common to reproducer construction. By the inclusion of the pins18 and the compressible gasket sleeves 19 oscillation on the part of thestylus bar from a neutral position will be resisted more and more as thestylus bar swings from its neutral position by the action of the sleeves19, which will be compressed to a more or less extent by the pins 18.However, by reason of the sleeves 19 a universal mounting will beprovided for the stylus bar which will admitof limited movement on thepart of the latter in any direction, that is, vertically, laterally-orto a given extent in any other direction, thus enabling the needle ofthe stylus bar to closely follow and conform to the minor variations ofthe record as well as the major. It is for this reason primarily thatthe present construction is believed to be capable of reproducing arecord with far neraeso ducing machines. Another important phase of thepresent invention rests in its simplicity in construction, and the easewith which. the stylus bar mounting may be assembled, without requiringthe services of expert or skilled workers, as is now common inreproduoer manufacture. The mounting may be assembled by providing thepins 18 with the rubber sleeves 19, in placing the pins and sleeveswithin the depressions 20 of the retaining blocks 21, and then bysecuring the blocks Within the sockets 11 through the medium of the twoscrews 22. it is apparout that this operation can. be very quicklyaccomplished and that setting or adjustment of the mounting, which mustin ordinary constructions be carefully performed, is entirelveliminated.

What is claimed is:

1. lo a sound reproducer for talking machines, a casing", spacedbearings provided upon said casing, a stylus bar movable with respect tosaid casing, outwardly extending trunnions fixed to said stylus bar andarranged to be received within said bearinis, transversely extendingpins carried by t e outer ends of said trunnions, and compressible meanssituated in said hearings in engagement with said pins.

2. In a sound reproducer for talking machines, a casing including spacedbearings, a stylus bar mounted for vibratory movement between saidbearings, said stylus bar including laterally extending trunnions havingthe outer ends thereof received within said bearings, projectionsextending at right angles to the longitudinal axis of said trunnions,and resilient means surrounding said projections and serving to rotatesaid trunnions to maintain said stylus bar in a normal position.

3. In a sound reproducer for talking machines, a casing including spacedsockets on the perimeter thereof, a stylus bar subject to oscillationrelative to said casing, said stylus bar including a pivotal mountingformed to embody aligned studs projecting laterally from said stylus barand having the outer ends thereof received Within said sockets, meansextending transversely with respect to the longitudinal axis of saidstuds, and sleeves of resilient material cooperative with said-means toadmit of limited move ment in any direction on the part or" said stylusbar and normally maintaining the latter in a neutral position.

a. In a sound reproducer for talking machines, a casing having" spacedsockets provided in the outer portion thereof, a stylus bar mounted foroscillation relative to said casing between said sockets, trunnion studsprojecting laterally from opposite sides of said stylus bar, the outerends of said studs being received within said sockets, pins passingtransversely through the outer ends of said studs, sleeves or" aresilient material surrounding said pins, and means for removablyretaining said studs within said sockets.

5. In a sound reproducer for talking machines, a casing having spacedsockets pro vided. in the outer portion thereof, a stylus bar mountedfor vibration relative to said casing and "positioned substantiallybetween said sockets, trunnion studs extending laterally from oppositesides of said stylus bar and having the outer ends thereof positionedwithin said sockets, pins fixed to rotate with said studs and extendingtransversely with respect thereto, sleeves of a re silient materialsurrounding said pins, and retaining blocks having depressions formedtill lit

therein for the reception of said pins and sleeves. said retainingblocks serving to re movably retain the outer ends of said studs withinsaid sockets.

In testimony whereof I afix my sigrmturea CARL SCRABIC.

